Home // International Journal On Advances in Systems and Measurements, volume 14, numbers 1 and 2, 2021 // View article


Clinopyroxene/Melt Partitioning: Models for Higher Upper Mantle Pressures Applied to Sodium and Potassium

Authors:
Julia M. Schmidt
Lena Noack

Keywords: high-pressure partition coefficients; partial melting; thermodynamic modelling; trace element redistribution; radiogenic heat sources

Abstract:
Mineral/melt partition coefficients describe the redistribution of trace elements during melting processes. They are highly influenced by changing pressure, temperature, and composition. We find that for sodium, partition coefficients rise in the order of two magnitudes from 0-15 GPa along the peridotite solidus temperature. Still, because of lacking high-pressure experimental data and the limited pressure range of most partitioning models, mantle and crust evolution models normally rely on constant partition coefficients. This is especially unfavorable for models which want to explore the thermal evolution of a terrestrial planet by tracing the heat producing elements. Based on a thermodynamic model, we parametrise sodium partitioning equations which are applicable from 0-12 GPa and 1410-2350 K. With the help of the sodium partitioning model, we calculate clinopyroxene/melt partition coefficients for the heat producing element potassium. Knowing both, the sodium and potassium partitioning behaviour, will help us to improve elemental redistribution calculations and therefore also thermal evolution models.

Pages: 125 to 136

Copyright: Copyright (c) to authors, 2021. Used with permission.

Publication date: December 31, 2021

Published in: journal

ISSN: 1942-261x